Abstracts

in situ treatment of coal tar at a field site as well as for the ex situ destruction of crude oil
tank bottoms and hydrocarbon impacted soils. The work is exploring the sensitivity of the
emissions to key system parameters (e.g., air flow rate, water content) and testing ways to
mitigate the emissions. This work is expected to demonstrate the very high rate of mass
destruction occurring during STAR/STARx application and also demonstrate how to understand,
minimize, and manage the emissions that may occur.
POSTER SESSION: Regional Groundwater
Systems
Thursday October 29, 16:40
Room: Regent
133 - Isotope and hydrogeochemical characterisation of
groundwater in a degrading permafrost environment in northern
Quebec, Canada.
Marion Cochand 1 , John Molson 1 , Jean-Michel Lemieux 1 , Johannes A.C. Barth 2 ,
Robert Van Geldern 2 , Richard Fortier 1 , & René Therrien 1
1
Centre d’études nordiques, Université Laval, Québec, Québec, Canada,
2
Friedrich-Alexander-Universität, Erlangen-Nürnberg, Germany
One consequence of global warming already being felt in northern Quebec is permafrost
thaw. Although its influence on groundwater resources is still largely unknown, it will
probably lead to increased groundwater recharge and changing flow dynamics.
A two square kilometer watershed in a discontinuous permafrost zone close to the Inuit
village of Umiujaq (northern Quebec, Canada) has been instrumented to assess the influence
of permafrost degradation on groundwater resources. The catchment is located
in the Tasiapik valley, which is mainly filled with glacial-fluvial and Quaternary marine
sediments. The area became deglaciated about 7500 years ago, and permafrost mounds
have formed within marine silts. The valley has two aquifers: an unconfined shallow sandy
aquifer located in the upper part of the valley, and a deeper confined aquifer in fractured
bedrock below the permafrost mounds.
Nine observation wells are being used to monitor both aquifers in a longitudinal transect
along the valley with measurements of groundwater levels and temperature profiles. In
addition, ground- and surface water, as well as precipitation and permafrost samples were
collected during three field campaigns in the summers of 2013 and 2014, and in November
2014 for hydrogeochemistry (dissolved metals and major anions), stable isotope
analysis (δ 18 O and δ 2 H) and dating ( 14 C and 3 H/ 3 He). The aim was to identify the origin
of groundwater (i.e. proportions from rain, snow and permafrost), to characterize groundwater
evolution along the flow path, and to understand seasonal dynamics together with
determination of residence time.
168 IAH-CNC 2015 WATERLOO CONFERENCE